Credit: The Associated Press

A high school student, who preferred not to be identified, smokes a cigarette in a de facto smoking area just off the property of Lewis-Palmer High School, in Monument, Colo., Thursday Feb. 20, 2014. A proposal to raise the tobacco age to 21 in Colorado is up for its first review in the state Legislature. The bipartisan bill would make Colorado the first with a statewide 21-to-smoke law.

DENVER — Two Western states with some of the nation's lowest smoking rates are considering cracking down even more by raising the tobacco age to 21.

Utah and Colorado lawmakers both voted favorably on proposals Thursday to treat tobacco like alcohol and take it away from 18- to 20-year-olds, a move inspired by new research on how many smokers start the habit as teenagers.

"By raising the age limit, it puts them in a situation where they're not going to pick it up until a much later age," said Marla Brannum of Lehi, Utah, who testified in favor of the idea there.